Method of producing solid-state color imaging devices

Abstract

In a solid-state imaging device wherein filters of the three primary colors in the mosaic filter configuration are stacked on a solid-state imager LSI in which a plurality of picture elements each consisting of a photoelectric conversion element and a scanning element are arrayed in the shape of a matrix; a method of producing a solid-state imaging device wherein the dimensions of filter layout patterns on exposure masks for the respective colors used in case of manufacturing the color filters of: T.sub.R <T.sub.B <T.sub.G where T R denotes the thickness of the red filter, T G that of the green filter and T B that of the blue filter, are smaller than the dimensions of the picture elements, and especially, the dimensions of the filter layout patterns on the exposure mask for manufacturing the green filters are the smallest.

What is claimed is: 
     
       1. A method of producing a color solid-state imager comprising the steps of integrating in the shape of a matrix on an identical semiconductor substrate a number of picture elements, each consisting of a photoelectric conversion element and a scanning element for addressing the photoelectric conversion element, and forming, by photoetching a film of material of which color filters are made, mosaic color filters stacked on the picture elements, characterized in that the color filters are formed by the use of at least one photoetching mask having filter patterns arrayed in the shape of a matrix for manufacturing said color filters, said filter patterns having dimensions that are reduced relative to dimensions of the picture elements. 
     
     
       2. A method of producing a color solid-state imager as defined in claim 1, characterized in that the color filters are formed by the use of a plurality of said photoetching masks to form corresponding color filters, in which dimensions of the filter patterns on said masks differ for respective colors forming said color filters. 
     
     
       3. A method of producing a color solid-state imager as defined in claim 2, characterized in that the filter patterns on the mask corresponding to the color filters requiring a greater film thickness have more reduced dimensions relative to the dimensions of said picture elements than the filter patterns corresponding to the color filters requiring a lesser film thickness. 
     
     
       4. A method of producing a color solid-state imager as defined in claim 2, characterized in that the color filters of the colors which are larger in the arrayal number thereof have the dimensions of their corresponding filter patterns on the mask reduced more relative to the dimensions of said picture elements than the dimensions of the filter patterns corresponding to the color filters of the colors which are smaller in the arrayal number. 
     
     
       5. A method of producing a color solid-state imager as defined in claim 1, characterized in that three masks are provided to form three sets of color filters on the picture elements, with the filter patterns on each of said masks having different dimensions, and with the filter patterns on the mask corresponding to the color filters requiring a greater film thickness having more reduced dimensions relative to the dimensions of said picture elements than the filter pattern corresponding to the color filters requiring a lesser film thickness. 
     
     
       6. A method of producing a color solid-state imager as defined in claim 5, characterized in that the three masks are used to form red, green and blue color filters. 
     
     
       7. A method of producing a color solid-state imager as defined in claim 1, to provide a complementary color configuration format of cyan, yellow, green and white, characterized in that a first mask having filter patterns which extend over a whole row of picture elements and a second mask having filter patterns corresponding to a second color are utilized, and wherein said color filters are formed by using said first mask to provide color filters of a first color extending over a whole row of picture elements, using said second mask to form color filters of a second color, superposing said first and second masks to form color filters of a third color, and leaving some of said picture elements uncovered with a color filter. 
     
     
       8. A method of producing a color solid-state imager as defined in claim 7, wherein said first color is yellow, said second color is cyan, and said third color is green. 
     
     
       9. A method of producing a color solid-state imager as defined in claim 1, wherein said filter patterns have dimensions that are reduced to an extent that, after formation of said color filters using the masks having said filter patterns, said color filters fill out the region of the corresponding picture elements. 
     
     
       10. A method of forming color filters on picture elements, in the shape of a matrix, of a color solid-state imager, comprising forming, by photoetching a film of material of which said color filters are made, mosaic (tiling) color filters stacked on the picture elements, characterized in that the color filters are formed by the use of at least one photoetching mask having filter patterns arrayed in the shape of a matrix for manufacturing said color filters, said filter patterns having dimensions that are reduced relative to dimensions of the picture elements. 
     
     
       11. A method of forming color filters on picture elements as defined in claim 10, characterized in that the color filters are formed by the use of a plurality of said photoetching masks to form corresponding color filters in which dimensions of the filter patterns on said masks differ for respective colors forming said color filters.